Biomedical subjects
Publications and source records attributed to O M Torres de Caballero.
A malformed male newborn was first diagnosed as having Smith-Lemli-Opitz syndrome. Extensive cytogenetic studies, including Q, G, C, R and T banding and BudR treatment, were applied, finally leading the authors to conclude that the patient had a partial 2p trisomy caused by direct duplication 2p14 to 2p23. This was a de novo chromosome abnormality, as both parents had normal karyotypes.
Two sibs with partial trisomy-5p are reported. Their father is the carrier of a balanced translocation 46,XY,t(4q+;5p-). Twelve cases of partial trisomy-5p--including our two patients--have been reported. The most common abnormalities found were mental retardation, short stature, dolichocephaly, prominent nasal bridge, prognathism, seizures, hypotonia, ear abnormalities, increased ulnar loops on the fingertips, and cryptorchidism in affected males.
A 5-month-old female was found with a 16q- trisomy; her mother was the carrier of a balanced translocation 46,XX,t(15p+;16q-)(15p12;16q11). This is the first report in the literature of a liveborn with this chromosome abnormality.
Minor abnormalities are described in an 11-month-old female in which a "de novo" trisomy 1q32 leads to lqter and a monosomy 3p25 leads to ter has been produced. The amount of the exceeding material in this case is less than that found in previous reports of partial trisomy 1q and in cases of parental 1q balanced translocations which has originated recurrent abortions.
Chromosome analysis in 23 specimens of Alouatta s. seniculus trapped in different localities of Colombia were examined with the C- and Q-banding techniques. The chromosome numbers (2n=44) showed variations from 2n = 43 to 2n = 45 involving three and five microchromosomes, respectively. Two specimens also showed a structural chromosome variation involving a pericentric inversion of the chromosome No. 13. Chromosome measurements revealed an X chromosome with a value significantly smaller to that established for the standard mammalian X chromosome.
The Q- and G-band analyses of Cebus capucinus, Cebus albifrons and Cebus apella are presented. The study is based on the results obtained from 18 specimens of the genus. For almost all of them, their exact locality is known. The data presented include the statement of two natural hybrids from C. capucinus and C. albifrons. On an evolutionary basis our results agree with the taxonomic concepts which postulate more similarity between C. capucinus and C. albifrons than between C. capucinus and C. apella. Furthermore, the comparative study of the Q- and G-band patterns indicates an independent chromosome evolution for C. albifrons and C. apella derived from a common ancestor more similar to C. capucinus.